Mold for casting



J. W. GALVIN.

MOLD FOR CASlINGr.4

` Patented Sept. 4, 1883.

l (No Model.)

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yielding of the core.

. iron mold, the shrinkage of the casting, lonthe iron mold would involve difficulty by the JOHN wyGALvIISI, PORTSMOUTH, OHIO..4

MOLDFOR CASTING.

a SPECIFICATION fofminglpartof Letters I? atent No. 284,407, dated september 4, 1883.

Application filed January 30, 1883. (No model.)

thickness as will afford the requisite strength,

in two or more pieces properly secured together. The iron of the mold is carefully finished in the interior to the correct form, and may be faced with lime `or other material to facilitate the production of sound castings with smooth surfaces.

material, analogous to the `cores long employed in iron-casting. The casting shrinks in the course of its manufacture; but the contraction g upon the core is allowed bythe crushing Or casting has imperfections which lock with the gitudinally or laterally, or both, is liable to induce serious mischief. Vhentthe exterior of the' casting is .to have projections which when produced in corresponding recesses in shrinkage, I Inake the recesses in the `i'ron larger than is required, and insert therein a close-fitting core of earthy matter, having just the required recess formed therein. Vhen the casting shrinks the 'projection therein ,changes its position relatively to the mold; but this change is allowed by the crumbling or other yielding of the core. No injury results to the iron mold or to the casting which is being produced therein. The cores by their yielding prevent the lcasting from becoming bound in the mold. They also prevent the casting from breaking the mold or itself.

` The accompanying drawings form a part of this specification, and represent what I consider thebest means of carrying out the invention as applied to the production of adrawhead for use onrailrOad-cars. rIhe desirabil ity'of Inaking such draw-heads of steel has been long recognized, but as heretofore constructed the molds were` not adapted fort-he successful production of such castings.`

' III the drawings, Figure l is a central loirV gitudinal section through the mold, several gcores, and the casting produced `by the aid lgthereof. `.The casting is represented darker than the iron mold. Fig. 2 is a correspond- Zing section ina plane at right angles to that of Alilig. l.

ISimilar letters of reference indicate corre= `sponding parts in both the figures.

I cast lthe draw-head in the upright posijtion, the mouth of the head being at the botV` tom of themoldj Q A is the bed-casting, recessed to'receive the Aother castings, and also to receive and center .the lower end of thecore.

`I produce hollow castings 5 by means of cores of properly-prepared earthy B C are sides or main portions of the mold. `D isa covering-piece. may be employed to hold `these'several parts fof the mold firmly in position.

E E,&c., are hoops, driven down vwithconzsiderable force from above. I

When the exterior of a i draw-head, as indicated by H2.

H is a core of baked earthy material, certain portions being designated, when necessary, by additional marks-of reference, as H H2. A goodcomposition for these cores is ten (10) of bank or lake sand, live (5) of com` mon moldingsand, and one (l) of wheat or rye iiour. They Inay be shaped in 'core-boxes rin the vordinaryway, and dried or bakedwat the ordinary temperature, so as to obtain strength and iirmness. yThe composition may be varied considerably. Instead of ilour, stale beer, la solution of. horse-dung, and other approved materials may be employed to secure the proper amount of adhesion. Venting may be effected in the ordinary way by inserting sticks, straws, or the like to produce a hole leading out through the print, preferablytaking out the stick or straw before the core is set in the mold.` rIhe core is large at that portion, H', which molds the large cavity in the draw-head to receive the link, It extends in smaller diameter the entire length of the Both ends are received in recesses in the end pieces, AA and D. rlhe core ismade considerablylarger than the casting which is to be produced. Its lower end is received in a recess in the casting A. Its upper end is received in al hole in the covering-piece l).

H3 -H4 are smoothly-rounded projections eX- Any efficient means tending outward from the main body of the core H H2. They are received in holes or core-prints in the parts B and C.

I is a core of baked earthy material matching in a large cavity in the part C, and having its small cavity adapted to receive aportion of the metal in the act of casting, and to thereby give the desired form-the converse of that of the recess in the core I.

M is the draw-head being cast. The main core HH2 produces a continuous hole throughout its length, and the branches H3H4produce corresponding holes in the casting M in the positions required. The recess in the core I produces the projection M, required for the efficient holding of the draw-head in place in thc car. The main core H H2 H3 H4 is represented as strengthened by stout wires h. They cult material, which requires for the highest success a nished surface of iron to mold the main exterior of the casting. The projection M and the general surface immediately adjacent thereto are molded by the core Iwith less perfection; but the imperfection thus introduced is too small to be of serious importance.

I have represented the mold as standing in an upright position, receiving the melted metal to form the casting M Mthrougha small hole, d, inthe coveringD. Thismay bevaried. All the details maybe varied within wide limits without departing from the principle or sacricing the advantages of the invention.

I have represented the invention as applied to the manufacture of draw-heads. This is a good example of the advantages, but there are many others equally requiring the allowance for change of form which this invention provides, while molding the general exterior surface with the perfection due to the iron molds A B G D.

In the shrinkage of the castingM M the portions H H2 of the core H are simply crushed' the mold remain of a relatively uniform diam- A eter and length, while the internal portion,

which is shaped within it, in changing from the temperature at which it first assumes a solid l form down to the temperature at which it is usually removed from the mold, contracts longitudinally. The form of the large end holds that part against movement, and consequently the small end makes a movement, shifting the hole produced by the core to a new position nearer the large end of the mold. rIhe core allows this movement to be produced without mischief.

The cores H and I are subjected to less distortion and crushing by virtue of the metal movportant,also,to employ yielding cores in place of rigidV cast-iron at these points to allow for the slight movements which are likely to occur there.

The bed-casting A may be secured to the side castings B C, by stout hooks or other means, (not shown,) or the joint made tight by inserting the whole a little distance in the ground or in any suitable flask and ramming damp earth around it. The whole mold may be buried in the earth, care being taken to secure by a rope of strawr each side, or by other efficient means, ample vent for any gases which may be discharged through the prints of the cores. To reduce the risk, of bubbles in the steel casting it is well to surface the interior of the castings with whitewash, preferably made from lime having a large` proportion of magnesia, sometimes known as dolomite. .f

I claim as my invention- The employment of cores of earthy material,

` ing toa less extent in shrinking; but it is im- In testimony whereof I have hereunto set my hand,l at Portsmouth, Ohio, this 25th day of January,l883,in the presence of two subscribing witnesses.

JOHN W-. GALVIN. Witnesses:

n WM. B. GRIER,

JOHN H. MCGRATH. 

